Tearing strip container



Can Company, New York, N. Y., a corporation of New Jersey Application December 31, 1954, Serial N 0. 479,016

9 Claims. (Cl. 220-54) The present invention pertains to a sheet metal container. More specifically it pertains to a tearing strip container having an improved side seam construction.

Tear-ing strip or rip strip sheet metal containers are old and well known in the art. Such containers usually are provided with soldered lock and lap side seams, the portion of the seam at the tearing strip being a lap portion. In recent years an organic adhesive or cement has been used instead of solder to bond together the various layers of the side seams. In such a cemented side seam it has been found of advantage to continue the lock portion of the seam through the tearing strip area and to interfold or double up the usual tearing strip tongue into the seam as one of the seam hooks so as to provide for the usual overlap projection of the tongue'on the outside of the can body to facilitate engagement of the tongue -with a conventional key and removal of the tearing strip to open the container.

However, the incorporation of a folded tongue as a hook in the side seam presents a d-ifliculty in that upon removal of the tearing strip, the hook formed from the folded tongue tends to pry up the other hook with which it is engaged and produces a protruding, sharp, metal edge. This projecting, sharp edge presents a serious cutting hazard to the user of the container. With tearing strip containers, having a so-called reclosure hinge top, i. e. those in which the tearing strip does not completely circumscn'be the body of the container leaving an integral hinge connection, this hazard is a continuing one because the outstanding sharp edge is not removed along with the tearing strip.

It has been proposed to obviate this difliculty by providing the portion of the inner hook which opposes the folded outer hook tongue and results in the oflending, outstanding, sharp edge with slits and weakening lines. With this construction, when the folded tongue is pulled out of the side seam in opening the container, the hook portion opposed to the "folded tongue Will adhere to and be torn out of the seam by this folded tongue portion due to the slits and weakening lines associated therewith.

However this proposal was found to be relatively unsatisfactory for a number of reasons. Certain operations, such as beading, collar insertion and double seaming are performed on the body after the side seam has been bonded. 'During these and other operations, it is virtually impossible to prevent flexing of the body wall. During such flexure the opposed edges of the slits are moved relative to one another whereby the thin layer of bonding material covering the slits is fractured, providing an unsealed portion in the side seam and a path for subsequent leakage. Also, unless the portion of the hook defined by weakening lines and slits adheres very strongly to the folded tongue, which condition does not always prevail, upon opening the container the folded tongue will merely pull away from the opposed hook portion lifting it up but not removing it, whereby the hazard which this construction was sought to prevent still remains. When using an organic adhesive instead of solder Q as the side seam bonding agent these difiiculties are es pecially pronounced since the force with which the cement bonds the metal layers together is relatively low, generally below that of solder.

-It is therefore an object of the present invention to provide a tearing strip container having an improved lock side seam in the area of the tearing strip.

Another object of the present invention is the provision of a tearing strip container having an improved lock side seam in the area of the tearing strip which, upon opening of the container will not result in a cutting hazard.

Still another object of the present invention is-to provide a tearing strip container having an improved lock side scam in the area of the tearing strip which is free of leak producing slits in this portion of the side seam.

A further object of the present invention is the provision of a tearing strip container having an improved lock side seam in the area of the tearing strip which side seam may be eifectively bonded and hermetically sealed by means of an organic adhesive as well assolder.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

I have found that the above and other objects are obtained by folding the key engaging tearing strip tongue in such a manner so as to form a body hook, and interlocking this hook with a body hook formed in the opposite side edge portion of the body, which latter hook has been notched to provide a hook of reduced circumferential width whereby upon opening of the canthe hook formed by folding the tongue readily slides out of engagement with the opposite, notched hook with little or no resulting distortion in the notched hook.

Referring to the drawing:

Figure 1 is a side view of a container, the body of which is made from the blank shown in Fig. 2 and having top and bottom ends thereon;

Fig. 2 is a plan view of a body blankfrom which the can body embodying the present invention is made, with parts broken away; i

Fig. 3 is 'an enlarged, fragmentary side View of the upper end of the body in the region of the side seam of the container, and including a portion of the tearing strip, shown partially torn away, as immediately after the side seam hooks at the tearing area have been disengaged by the winding of the tearing strip on the opening key;

Fig. 4 is a detailed, enlarged, horizontal sectional view taken substantially along the line 4-4 of Fig. 3;

Pig. 5 is a view similar to Fig. 4 but showing the side seam hooks in the tearing strip area as immediately before disengagement of the hooks by winding the tearing strip on the opening key;

Fig. 6 is a detailed horizontal sectional view taken substantially along the line- 66 of Fig. 1; i

Fig. 7 is a detailed horizontal sectional view taken substantially along line 77 of Fig. 1; and

Figs. 8 and 9 are enlarged fragmentary plan views showing modifications of a notch in one side edge of the body blank.

As a preferred or exemplary embodiment of the instant invention the drawings illustrate a sheet metal container comprising a body 10 (Fig. 1) having a lock side seam 1i and upper and lower ends 12, 13 joined to the body It) in a conventional manner as by upper and lower end seams 14 and 15 respectively.

Spaced belowthe upper end seam 14 and completely circumscribing the body 10 is a bead 1-6. Disposed between bead 16 and the upper end seam 1-4, a pair of spaced and parallel score lines 23 define a tearing strip 24 ter minating in a tearing strip tongue 25 disposed on the Patented June 25, 1957 v outside of body 10 for engagement with an opening key when the container is opened.

Can body 10 is made from a flat blank 17 (Fig. 2)

- tance between edge 21 and fold line 28 is practically the blank to a point 22 spaced inwardly from side edge 21." The tearing strip tongue 25 'is' integral with blank -17 and extends or projects from sideedge 20 inalignment with tearing strip 24. A cut away portion or notch -26 is disposed in edge 21 also in alignment with tearing strip 24. In a well known manner side edges 20, 21 are folded in opposite directions along fold lines 27, 28

to form 'outer and inner body hooks 30 32 (Fig. '7) respectively, which hooks are interlocked and bonded as by an organic cement 33 or solder to form the side seam 11. The portion of side seam 11 disposed between score lines 23 is composed of a folded tongue portion 29 and a notched or reduced width hook portion 31. (Figs. 4 to 6.) p

In the formation of portion 29 of outer hook 30, tongue 25 is reversely bent along line 34 (Fig. 2), which is in alignment with side edge 20, forming a hook of double thickness in the area set off between score lines 23 in the side seam (Fig. 6) and enabling tongue 25 to extend onthe outside of can body 10 where it can be grasped by a tearing strip removal key 36.

Notch 26 disposed in portion 31 of inner hook 32 does 'not extend the full width of the book, i. e. the depth of notch 26 is less than the distance between edge 21 'and foldline 28. To provide sufficient bonding surface and thereby a tight, hermetic side seam, it is found that the depth of notch 26 must not be equal to or greater than the width of book 32; but on the contrary the depth of the notch must merely reduce the width of book 32 at the portion 31 so as to leave remaining a sufficient width of book to engage with the folded tongue portion 29. Due to its alignment with tearing strip 24, notch 26 is disposed opposite the fold of the tongue 25 in the finished side seam 11. Because of the shorter width of hook 32 in the portion 31 due to the notch 26 there exists in this portion of the side seam a void 38 (Figs. '4 and Void or gap 38 acts as a reservoir to hold a bonding material, e. g. cement or solder 33, whereby excess bonding agent is present in this portion of the side seam to provide a more effective seal as best seen in Fig. 6.

'(Figs. 4 and 5) of portion 31. The effect of the disengagement is that there is produced little or no resultant force against the underside of portion 31 which would tend to straighten it or cause it to assume a position projecting or jutting outwardly from the body wall of the container. Thereafter the remainder of the tearing strip 24 may be removed from the can body by the continued winding of the strip on the shank of key 36.

In the preferred embodiment set forth above the longitudinal length of notch 26 is substantially equal to the distance between the score lines 23 and the depth of the notch is approximately /3 the distance between edge 21 and fold line 28. These dimensions of notch 26 give suflicient contact area between portions 29 and 31 to produce an effective, leak-proof seal when these two portions are bonded together; 'and at the same time leave sufficient clearancegap 38. to allow the folded tongue portion 29 to be disengaged from the inner hook portion 31 with substantially no distortion of the latter. Although the above notch depth dimension is preferred, a notch depth of approximately from /5 to /2 the die operable for carrying out the instant invention.

Fig. 8 illustrates a modified notch 46 the sides of which are substantially perpendicular to the base of the notch and which base has a longitudinal length approximately equal to the distance between the score lines 53. With this configuration the overall length of notch 46 is substantially equal to the distance between score lines 53. However, the sides of notch 46 need not be perpendicular but may be sloping as in notch 26 in which case the overall longitudinal length of notch 46 would be slightly greater than the distance between score lines 53.

Another modified notch 56 is shown in Fig. 9. In this modification the defining edge of the notch is circular or arcuate. The overall longitudinal length of notch 56 is approximately equal to the distance between the score lines 63. However here also, as with notch 46, the length of notch 56 may be extended so as to be slightly greater than the distance between score lines 63 and still provide sufficient bonding surface between the reduced hook portions and the folded tongue portion of the hooks to effect a tight, hermetic seal.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. A tearing strip container comprising a body member having end members attached thereto, said body member having a longitudinal side seam composed of opposed interengaged hooks, spaced parallel score lines in said body defining therebetween a tearing strip terminating at the edge of one hook of said side seam, said tearing strip adjacent said one book edge terminating in an integral tongue projecting from said side seam, the inner portion of said tongue being folded back on said one hook, said tongue being engageable with an opening key for removing said tearing strip to open the container, and an open notch in the other book opposed to and overlapping said tongue fold to reduce the circumferential width of said other hook, whereby said other hook is substantially undistorted upon separation and disengagement of said folded tongue therefrom when opening said container. e

2. A tearing strip container comprising a body member having end members attached thereto, said body member having a longitudinal side seam composed of interengaged inner and outer hooks, spaced parallel score lines in said body defining therebetween a tearing strip terminating at the edge of said outer hook, said tearing strip adjacent said outer hook edge terminating in an integral tongue projecting from said side scam, the inner portion of said tongue being folded back on said outer hook, said tongue being engageable with an opening key for removing said tearing strip to open the container, and an open notch in said inner hook opposed to and overlapping said tongue fold to reduce the circumferential width of said inner hook, whereby said inner hook is substantially undistorted upon separation and disengagement of said folded tongue therefrom when opening said container.

3. A tearing strip container comprising a body member having end members attached thereto, said body member having a longitudinal side seam including interengaged inner and outer hooks, spaced parallel score lines extending from the edge of said outer hook around said body and terminating short of said side seam, said score lines defining a tearing strip therebetween, said tearing strip adjacent said outer hook edge having an integral tongue reversely folded on said outer hookand projecting onthe outside of said body for removing said tearing strip to open the container, and an open notch in said inner hook opposed to and overlapping said tongue fold to reduce the circumferential width of said inner hook, whereby said inner hook is substantially undistorted upon separation and disengagement of said folded tongue portion therefrom when opening said container.

4. The container defined in claim 1 in which the length of said open notch is greater than the width of said opposed folded tongue.

5. The container defined in claim 1 in which the length of said open notch is substantially equal to the width of said opposed folded tongue.

6. The container defined in claim 1 in which the sides of said notch extend at an angle from the base thereof.

7. The container defined in claim 1 in which said notch is of arcuate configuration.

8. A metal blank for a container body comprising a flat sheet having opposed parallel side edges extending between opposed parallel end edges, marginal portions of said sheet adjacent said side edges being adapted to be reversely bent along predetermined fold lines to form interengageable body hooks, a pair of spaced parallel score lines extending from one side edge to a point spaced inwardly of the other side edge, said score lines defining a tearing strip therebetween, a tongue integral with one of said sheet hook portions and projecting from said tearing strip at said one side edge, and an open notch in the hook portion of said other side edge of the sheet and 6 disposed in alignment with said tearing strip, the depth of said notch being less than the width of said body hook portions of said sheet.

9. A metal blank for a container body comprising a flat sheet having opposed parallel side edges extending between opposed parallel end edges, marginal portions at the sides of said sheet being adapted to be reversely bent along predetermined fold lines to form interengageable inner and outer body hooks, spaced parallel score lines extending from said outer hook to a point adjacent to and spaced inwardly of said fold line of said inner hook, said score lines defining a tearing strip therebetween, a tongue integral with said outer hook portion of the sheet and projecting from said tearing strip and an open notch in said inner hook portion of the sheet and disposed in alignment with said tearing strip, the depth of said notch being less than the width of said inner hook portion of said sheet.

References Cited in the file of this patent UNITED STATES PATENTS 2,279,668 Forsberg Apr. 14, 1942 2,365,112 Schrader et al. Dec. 12, 1944 2,660,332 Henchert Nov. 24, 1953 2,692,699 Pelosi Oct. 26, 1954 

